Trial Outcomes & Findings for Phase I/II Study of SRP-4053 in DMD Patients (NCT NCT02310906)

The study was conducted at 5 sites in the France, Italy, United Kingdom and United States from 13 January 2015 to 25 March 2019.

Study conducted in 2 parts: Part 1 and Part 2. When Part 1 was completed and cumulative safety data was reviewed by an independent Data Safety Monitoring Board (DSMB), Part 2 was conducted.

All participants who were previously randomized in Part 1 were moved to Part 2a (after completion of Part 1, n=12) along with 13 new participants. Hence, total number of participants in Part 2a were 25. In Part 2b, 14 untreated new participants were enrolled.

Adverse event (AE) was any untoward medical occurrence in a clinical trial participant, which does not necessarily have a causal relationship with the investigational drug. A Serious adverse event (SAE) was an AE resulting in any of the following outcomes: death; Life-threatening event; Required or prolonged inpatient hospitalization; persistent or significant disability/incapacity; congenital anomaly. TEAEs were defined as AEs that were reported or worsened on or after the start of study drug dosing through 12 weeks. TEAEs included both Serious TEAEs and non-serious TEAEs.

Laboratory parameters included hematology, serum chemistry (SC), urinalysis and coagulation. Number of participants with at least one potentially clinically significant abnormal finding were reported as TEAEs. The Investigator determined whether abnormal assessment results were potentially clinically significant or not. Potentially clinical significance was defined as any variation in assessment results that had medical relevance resulting in an alteration in medical care.

Vital sign parameters included systolic blood pressure (SBP), diastolic blood pressure (DBP), heart rate (HR), and body temperature. Number of participants with at least one potentially clinically significant abnormal vital signs findings were reported as TEAEs. The Investigator determined whether abnormal assessment results were potentially clinically significant or not. Potential clinical significance was defined as any variation in assessment results that had medical relevance resulting in an alteration in medical care.

Physical examinations were performed by the Investigator, or qualified study staff. A full physical examination included a review of general appearance, head, eyes, ears, nose and throat, heart, lungs, abdomen, extremities, skin, lymph nodes, musculoskeletal, and neurological systems. Number of participants with potentially clinically significant abnormalities in physical examinations were reported. Potentially clinically significant abnormalities in physical examinations were based on Investigator's discretion.

Twelve-lead ECGs were performed at a consistent time of day throughout the study. Electrocardiograms were performed only after the participant was in the supine position, resting, and quiet for a minimum of 15 minutes. The ECG was manually reviewed and interpreted by medically qualified personnel. Number of participants with potentially clinically significant abnormalities in ECG reported as TEAEs presented here. The Investigator determined whether abnormal assessment results were potentially clinically significant or not.

Standard, 2-dimensional ECHOs were performed at a consistent time of day throughout the study. Cardiac function events included cardiomegaly, tachycardia, and dyspnoea. The ECHO was reviewed and interpreted by medically qualified personnel. Number of participants with potentially clinically significant abnormalities in ECHO were reported.

6MWT was performed by standardized procedures for all participants. Participants were asked to walk a set course of 25 meters for 6 minutes (timed), and the distance walked (in meters) was recorded. Change from baseline in 6MWT distance at Week 144 in total golodirsen group was reported.

6MWT was performed by standardized procedures for all participants. Participants were asked to walk a set course of 25 meters for 6 minutes (timed), and the distance walked (in meters) was recorded. Change from baseline in 6MWT distance at Week 144 in untreated group (non-exon 53 amenable participants) was calculated.

Change from baseline in dystrophin protein levels (in muscle biopsy samples) was determined by Western blot in total golodirsen group.

Maximum Concentration (Cmax) of golodirsen in plasma was evaluated.

Time to reach maximum plasma concentration (Tmax) of golodirsen was evaluated.

Area under the concentration-time curve from time zero extrapolated to the infinity was evaluated.

Volume of distribution was defined as the theoretical volume in which the total amount of drug would need to be uniformly distributed to produce the desired plasma concentration of a drug. Apparent volume of distribution at steady state of golodirsen was evaluated.

T1/2 is the time measured for the plasma concentration of drug to decrease by one half. T1/2 of golodirsen was evaluated.

Drug clearance is a quantitative measure of the rate at which a drug substance is removed from the blood.

MRT= AUMCinf/AUCinf, where AUMCinf is the area under the first moment curve from time 0 extrapolated to infinite time, calculated using the linear/log trapezoidal method. Mean residence time of golodirsen was evaluated.

Renal clearance was calculated using the partial AUC0-24 from the non-compartmental analysis in plasma and AE0-24. AUC0-24 was defined as area under the plasma concentration-time curve, from time 0 to 24 hours after completion of dosing. AE0-24 was defined as total cumulative amount excreted from 0 to 24 hours. Summarized data of all urine collection intervals are reported.

FVC was the total amount of air exhaled during the forced expiratory volume test that was measured during spirometry and the most important measurement of lung function. This test required participant to breath into a tube connected to a machine that measures the amount of air that can be moved in and out of the lungs after taking an inhaled bronchodilator medicine which was used to dilate participant bronchial (breathing) tubes. Percent of predicted FVC = (observed value)/ (predicted value) \* 100%.

FVC was the total amount of air exhaled during the forced expiratory volume test that was measured during spirometry and is the most important measurement of lung function. This test requires participant to breath into a tube connected to a machine that measures the amount of air that can be moved in and out of the lungs after taking an inhaled bronchodilator medicine which was used to dilate participant bronchial (breathing) tubes. Percent of predicted FVC = (observed value)/ (predicted value) \* 100%.

Change from baseline in dystrophin Intensity levels (in muscle biopsy samples) was determined by Immunohistochemistry in total golodirsen group.

Percent change from baseline in Exon 53 skipping (in muscle biopsy samples) was determined by reverse transcription polymerase chain reaction in total golodirsen group.

Percent change from baseline in dystrophin positive fibers (in muscle biopsy samples) were determined by Immunohistochemistry at Week 48 in total golodirsen group.